Never Underestimate a Marine
by LuffyForKing
Summary: Monkey D. Garp returns to his hometown to discover that his 7 year-old grandson, Luffy, has eaten a Devil's Fruit. The marine hero is not happy.


**Never Underestimate a Marine**

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Monkey D. Garp was not happy.

He was away on business for only a few months and upon his return he discovers that his grandson has made an undesirable friend.

Makino ducked in to the back of the bar as the marine hero barged in, knowing that she would be scolded as soon as he saw the straw hat that sat proudly upon his grandson's head.

Sure enough, the infamous hat caught Garp's attention. "Luffy…what is this?" the marine asked, a scowl on his gruff face as he eyed the hat.

"This is a hat Shanks gave me," the boy smiled widely, placing his hand on his new treasure, "I'm going to give it back to him after I become a super strong pirate!"

The young boy's words came out innocently; unaware of the fury they would receive.

"I knew that damn hat looked familiar!" Garp growled upon hearing the red-hair pirate's name, his eyes piercing daggers through the hat, "Get rid of it. You don't need it. You're becoming a strong marine admiral."

"I'M GOING TO BECOME THE PIRATE KING!" a young Luffy shouts defiantly, puffing his cheeks out as a twitch develops above his grandfather's eye. _What is this nonsense?_ _Damn that red-hair_, the old man seethed inwardly, _he better hope that he doesn't run in to me anytime soon._

"LIKE HELL YOU WILL!" Garp shouted, bringing his fist down on the seven year-old's head. "YOU ARE GOING TO BECOME A STRONG MARINE!"

Much to his grandfather's surprise, the young, aspiring pirate did not flinch at the impact. A smirk spread across the young boy's face.

"WHAT ARE YOU SMIRKING ABOUT?" Garp the hero fumed, grabbing the corner of Luffy's cheek. Unexpectedly, the young boy's face stretched along with the pull. Garp's jaw dropped and his eyes widened as he proclaimed, "WHAAAAAA?!"

"I ate a devil's fruit!" the little boy said, his smile growing wider, "I'm a rubber man now!"

Garp's eyes widened even more. _What the hell happened while I was gone?!_

His twitch re-appeared as the heat rushed to his face. "Is this that red-hairs doing?" he asked, his voice lowered, but angry. The little boy's smile started to relinquish at his grandfather's threatening tone. Luffy knew exactly how frightening the old man could be.

"I ate it myself-" the boy stuttered, tears threatening to fall from his eyes.

"I'll kill him!" Garp proclaimed, a fire burning in his eyes before adding, "and you too, Makino! Don't think that I am unaware that you are listening!" The tavern owner shuttered from her hiding spot, her face turning pale as she mouthed, "shit" to herself. She knew that Garp cared about nothing more than he did his grandson. She also knew that she would get partial blame for the boy's friendship with Shanks. This knowledge was unsettling.

Garp lifted his hands in the air, his right hand still clasped to Luffy's face, which stretched even farther. He looked his grandson over curiously, anger overtaking any possibility of rationality. All the marine hero wanted to do was kill that damn red-haired pirate for brainwashing his cute, little grandson._  
_

"Yeah wite," the boy mumbled, almost inaudible due to the fact that his mouth was stretched larger than his entire body, "Shanks would kick yer ass."

The old man's gaze turned robotically towards the boy, a cruel smile dancing across his lips that made Luffy squirm in fear. Any shred of pity the old man felt towards the little boy disappeared. The young boy attempted to wriggle his way out of his grandfather's strong grip, completely aware of his blunder, but he was too late.

The marine hero brought his haki-laced fist down on the boy's head, a large bump surfacing immediately upon impact.

"OWWW!" Luffy screamed, rubbing his head, "but I'm rubber, that shouldn't hurt!"

The menacing smile did not leave the old man's lips as he whispered cruelly, "Don't underestimate a marine, Luffy. After all, you're going to be one, one day."

…

Makino sighed in relief for herself as the old man dragged the little boy out of the bar, still holding the child's cheek. She whispered a prayer of safety for Luffy as she heard Garp declare, "MAYBE A FEW DAYS IN THE JUNGLE BY YOURSELF WILL STRAIGHTEN YOU OUT." Luffy's wails of protest started to fade away and the tavern owner made her way to the center of the bar. _I guess I dodged the bullet for now_, she thought only to have her hopefulness crushed by a loud voice declaring, "I'LL BE BACK MAKINO, YOU BASTARD."

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**Author's Note:/** I hope you enjoyed the story, reviews are much appreciated! I found myself wondering how Garp would react to Luffy eating a Devil's Fruit and becoming acquainted with Shanks, so I figured I would give it a shot. I tried going with a more humorous than serious approach, mostly because that is what I prefer. What do you think?


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